Center Coordinates

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This example showcases how to build a Flutter app featuring an interactive map and how to center the camera on map WGS coordinates

How it works

The example app demonstrates the following features:

• Center the map on predefined coordinates.
• Optionally use an animation to smoothly transition the map view.

Initial map view

Map view after centering on coordinates

UI and Map Integration

main.dart

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Center Coordinates',
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key});

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  late GemMapController _mapController;

  @override
  void dispose() {
    GemKit.release();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.deepPurple[900],
        title: const Text('Center Coordinates',
            style: TextStyle(color: Colors.white)),
        actions: [
          IconButton(
              onPressed: _onCenterCoordinatesButtonPressed,
              icon: const Icon(
                Icons.adjust,
                color: Colors.white,
              ))
        ],
      ),
      body: GemMap(
        key: ValueKey("GemMap"),
        onMapCreated: _onMapCreated,
        appAuthorization: projectApiToken,
      ),
    );
  }

This code sets up the basic structure of the app, including the map and the app bar. It also provides a button in the app bar for centering the map on specific coordinates.

main.dart

// The callback for when map is ready to use.
void _onMapCreated(GemMapController controller) async {
  // Save controller for further usage.
  _mapController = controller;
}

void _onCenterCoordinatesButtonPressed() {
  // Predefined coordinates for Rome, Italy.
  final targetCoordinates =
      Coordinates(latitude: 41.902782, longitude: 12.496366);

  // Create an animation (optional).
  final animation = GemAnimation(type: AnimationType.linear);

  // Use the map controller to center on coordinates.
  _mapController.centerOnCoordinates(targetCoordinates, animation: animation);
}

This code handles centering the map on the predefined coordinates for Rome, Italy. The GemMapController is used to perform this action, and an optional animation is provided for a smooth transition.